259 research outputs found
Influence of Storm Surge on the Inundated Potential in the Coastland
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Virtual reality training and assessment in laparoscopic rectum surgery
Background: Virtual-reality (VR) based simulation techniques offer an efficient and low cost alternative to conventional surgery training. This article describes a VR training and assessment system in laparoscopic rectum surgery. Methods: To give a realistic visual performance of interaction between membrane tissue and surgery tools, a generalized cylinder based collision detection and a multi-layer mass-spring model are presented. A dynamic assessment model is also designed for hierarchy training evaluation. Results: With this simulator, trainees can operate on the virtual rectum with both visual and haptic sensation feedback simultaneously. The system also offers surgeons instructions in real time when improper manipulation happens. The simulator has been tested and evaluated by ten subjects. Conclusions: This prototype system has been verified by colorectal surgeons through a pilot study. They believe the visual performance and the tactile feedback are realistic. It exhibits the potential to effectively improve the surgical skills of trainee surgeons and significantly shorten their learning curve. © 2014 John Wiley & Sons, Ltd
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Continuous precipitation of ceria nanoparticles from a continuous flow micromixer
Cerium oxide nanoparticles were continuously
precipitated from a solution of cerium(III) nitrate and ammonium
hydroxide using a static microchannel T-mixer. Tmixer
synthesis results were compared with synthesis results
from batch precipitation. Findings show that the method of
mixing is important in the ceria precipitation process. Uniform
porous film structures and nanorods were produced
when the particle chemistry was synthesized using T-mixing
followed by spin coating. Batch mixing, when using higher
NH₄OH feed concentrations followed by spin coating, was
characterized by the heavy agglomeration of nanoparticles.
Similar, high aspect ratio nanorods were produced when
feed conditions in both batch mixing and T-mixing were
identical demonstrating that the momentum effects of continuous
microchannel T-mixing did not impact the synthesis
process. In addition, it was found that the micromixing
approach reduced the exposure of the Ce(OH)₃ precipitates
to oxygen, yielding hydroxide precipitates in place of CeO₂
precipitates. The key advantage of the micro-scale T-mixing
approach is higher throughput which is important for the
scaling of ceria nanoparticle production.Keywords: Ceria, Nanoparticles, Continuous flow synthesis, Microreactor, MicromixerKeywords: Ceria, Nanoparticles, Continuous flow synthesis, Microreactor, Micromixe
In vitro assay to estimate tea astringency via observing flotation of artificial oil bodies sheltered by caleosin fused with histatin 3
AbstractAstringency, a sensory characteristic of food and beverages rich in polyphenols, mainly results from the formation of complexes between polyphenols and salivary proteins, causing a reduction of the lubricating properties of saliva. To develop an in vitro assay to estimate the astringency of oolong tea infusion, artificial oil bodies were constituted with sesame oil sheltered by a modified caleosin fused with histatin 3, one of the human salivary small peptides. Aggregation of artificial oil bodies was induced when they were mixed with oolong tea infusion or its major polyphenolic compound, (−)-epigallocatechin gallate (EGCG) of 100μM as observed in light microscopy. The aggregated artificial oil bodies gradually floated on top of the solution and formed a visible milky layer whose thickness was in proportion to the concentrations of tea infusion. This assay system was applied to test four different oolong tea infusions with sensory astringency corresponding to their EGCG contents. The result showed that relative astringency of the four tea infusions was correlated to the thickness of floated artificial oil bodies, and could be estimated according to the standard curve generated by simultaneously observing a serial dilution of the tea infusion with the highest astringency
Nanoscale III-V Semiconductor Photodetectors for High-Speed Optical Communications
Nanophotonics involves the study of the behavior of light on nanometer scale. Modern nanoscale semiconductor photodetectors are important building blocks for high-speed optical communications. In this chapter, we review the state-of-the-art 2.5G, 10G, and 25G avalanche photodiodes (APDs) that are available in commercial applications. We discuss the key device parameters, including avalanche breakdown voltage, dark current, temperature dependence, bandwidth, and sensitivity. We also present reliability analysis on wear-out degradation and optical/electrical overload stress. We discuss the reliability challenges of nanoscale photodetectors associated with device miniaturization for the future. The reliability aspects in terms of high electric field, Joule heating, and geometry inhomogeneity are highlighted
Ναυτικό μουσείο στο δέλτα του Φαλήρου
Σημείωση: το κυρίως κείμενο και το συνοδευτικό υλικό του διατίθεται σε ξεχωριστό ενιαίο αρχείο
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